A turbine is a rotary mechanical device that converts energy from a fluid flow to work, such as by providing thrust or rotary mechanical power. A turbine is a turbomachine with at least one moving part called a rotor assembly, which is a shaft or drum onto which blades are attached. Moving fluid acts on the blades so that they move and impart rotational energy to the rotor.
A proportional-integral-derivative (PID) controller is a control loop feedback system that is widely used in industrial control systems. A PID controller determines the difference between a measured process variable and a desired set point and calculates an error value. The PID controller adjusts process control outputs to reduce the error value.
Tuning of PID controllers can be a difficult task, especially in applications such as turbine control where multiple, possibly conflicting, performance objectives such as fast transient response and high stability of the turbine output are desired. Tuning of PID controllers can also be difficult when the turbine is unloaded, since unloaded turbines are systems with little damping and high acceleration, which are unusual conditions within the process control industry. In practice, such applications can exceed the skills or training of turbine operations personnel, and PID tuning configurations are thus often adjusted repeatedly through trial-and-error until the system provides an acceptable, but not always optimal, level of performance.